Which burns more calories?

Which form of running is more efficient: treadmill or running outside?

I put that question in Google's search bar and was surprised to find the first hit, an article from Shape magazine, showed no discernible difference in calorie burn until you start running a 10-mile-an-hour pace. Some sources confirmed this finding, while others touted one or the other.

One article championed the treadmill because it's there. If you've invested your hard-earned cashmoneybucks in the equipment, and you don't have to drive someplace to use it, and you can use it in all weather conditions, then it's the most efficient way to blast away fat.

I didn't create a spreadsheet listing the pros and cons from each author's research, but the general impression I get is that outdoor running probably burns more calories. The running surface is uneven and sometimes hilly, and your body does have to work harder to overcome wind resistance and dodge potholes.

Sometimes, though, it's the treadmill or nothing at all. Raising the incline will increase the intensity and provide a more challenging workout if you're running indoors.

My preference is to take it outside. I've used the treadmill a couple times recently, though, due to weather, and am surprised at how much harder it seems to be on my knees. However – I'm running constantly at 5 to 5.2 mph at a 2 to 3 percent incline on the treadmill. When I'm outside, I mostly walk or jog at a 4 mph pace.

I could do neither without the music on the Shuffle. [Well, of course I could, but it would be excruciatingly boring, in my not-so-humble opinion.]

Yesterday I did six miles on the treadmill in 71 minutes. One cannot get more bored.

Moving on to knitting … I've finished the sleeves of the Oat Couture Seville Jacket, and have about a third of the cabled edge completed. I'll block the sleeves today, and sew them into the body tomorrow. I made my jacket a bit longer – it's supposed to be cropped, but that's not a good look for me – and I also made wrist-length sleeves instead of three-quarter, as the pattern instructs. Since the body is longer, I'll need more length on the edging, which goes all the way around the fronts, back neck and lower edge of the piece.

What I'm planning to do is knit about 90 inches – talk about boring! – and then block it. That will make sewing it onto the sweater a little easier. I think 90 inches will be too much, but in this case I'd rather rip some out to get the right amount, since I want it all blocked before I start sewing. [You non-knitters can uncross your eyes now.]

I thought my next project would be Knitty's Tilt, but my daughter-in-law has two friends who are having three babies this fall, and I'd much rather work on quick-to-knit baby things for a while. The expected twins are a boy and a girl, so I think I'll make a couple of lightweight cream-colored cardigans with some colorful Fair Isle patterning. Maybe a dark rose for the girl and dark green for the boy. No namby-pamby pinks and blues here! The other baby's gender will be a surprise, but I've made a cream-colored, Wonderful Wallaby, to which I add some Aran patterning, for other babies in the past, and it works for either sex. So the Tilt will be on deck.

If you have an opinion, some personal experience or a definitive source that answers the 'which is better at burning calories: treadmill or outdoor running' question, I'd love to hear it!